Community dynamics generates complex epidemiology through self-induced amplification and suppression

The development of quantitative models of outbreaks is key to their eventual control, from human and computer viruses through to social (and antisocial) activities. Standard epidemiological models can reproduce many general features of outbreaks. Unfortunately, the large temporal fluctuations which often dominate real-world data are thought to require more complicated, system-specific models involving super-spreaders, specific social network topologies and rewirings, and birth-death processes. However we show here that these large fluctuations have a generic explanation in terms of underlying community dynamics. Communities increasing (or decreasing) in size, act as instantaneous amplifiers (or suppressors) yielding a complex temporal evolution whose features vary dramatically according to the relative timescales of the community dynamics. We uncover, and provide an analytic theory for, a novel epidemiological phase transition driven by the population's response to an outbreak. An imminent epidemic will be suppressed if individual communities start to break up more frequently or join together less frequently, but will be amplified if the reverse is true

Galaxy populations in the Antlia cluster - III. Properties of faint early-type galaxies

(Abridge) We present a new analysis of the early-type galaxy population in the central region of the Antlia cluster, focusing on the faint systems like dwarf ellipticals (dE) and dwarf spheroidals (dSph). We confirm 22 early-type galaxies as Antlia members, using GEMINI-GMOS and MAGELLAN-MIKE spectra. Among them, 2 belong to the rare type of compact ellipticals (cE), and 5 are new faint dwarfs that had never been catalogued before. In addition, we present 16 newly identified low surface brightness galaxy candidates, almost half of them displaying morphologies consistent with being Antlia's counterparts of Local Group dSphs, that extend the faint luminosity limit of our study down to MB = -10.1 (BT = 22.6) mag. We built an improved CMR in the Washington photometric system, i.e. integrated T1 magnitudes versus (C - T1) colours, which extends \sim 4 mag faintwards the limit of spectroscopically confirmed Antlia members. When only confirmed early-type members are considered, this relation extends over 10 mag in luminosity with no apparent change in slope or increase in colour dispersion towards its faint end. The intrinsic colour scatter of the relation is compared with those reported for other clusters of galaxies; we argue that it is likely that the large scatter of the CMR, usually reported at faint magnitudes, is mostly due to photometric errors along with an improper membership/morphological classification. The distinct behaviour of the luminosity versus mean effective surface brightness relation at the bright and faint ends is analyzed, while it is confirmed that dE galaxies on the same relation present a very similar effective radius, regardless of their colour. The projected spatial distribution of the member sample confirms the existence of two groups in Antlia, each one dominated by a giant elliptical galaxy and with one cE located close to each giant.Comment: 19 pages, 9 figures, 5 tables. Accepted for publication in MNRA

Decent work and healthy employment: a qualitative case study about Colombian millennials

The purpose of this paper is to show how a group of Colombian millennials perceive different aspects of working life and how their ideas about job satisfaction, professional expectations, and levels of autonomy are related to contemporary demands about inclusion, diversity, equity, autonomy, and control. With this objective, 167 semi-structured interviews were conducted with millennials who work at 10 Colombian companies from the manufacturing and service sectors, located in the 5 main cities of the country. With a qualitative approach in the interviews, the research team used a strategy inspired by the technique of generating visual structures associated with grounded theory. It is concluded that new generations of Colombian workers know of the importance of rewards and autonomy in work and are more critical and less passive in the face of unhealthy working conditions. At the same time, their conduct and speeches are the consequence of the characteristics of the Colombian labour market. The document responds to the need to deepen the debates on welfare and happiness in organizations and to include the demands of millennials in the reflective and political horizon of the ideas of healthy employment and decent work. In practice, this article seeks to demystify ideas about millennials in Colombia and critically contribute to reflection on intergenerational relations in organizations and salary and welfare models. As a Latin American case, it is an original contribution that avoids the common places and the frivolity with which the insertion of the new generations into the working world has been analysed

Millennials and the gender wage gap: Do millennial women face a glass ceiling?

This study aims to measure the gender wage gap among millennial workers in Colombia and determine if there is a marked wage difference between millennial women and men. Further, this study analyzes whether millennial women face a glass ceiling, that is, if there is a larger gender wage gap among workers earning relatively high wages. The study data included a sample of 2,144 millennial workers employed in 11 organizations located in the five main cities of Colombia. Oaxaca–Blinder econometric methods of wage decomposition were used to calculate both raw and adjusted gender wage gaps. The latter results in estimating the gender wage gap while controlling for observable characteristics related to individual, family, and labor. The results show that millennial workers in Colombia face gender inequality in the labor market and that professional millennial women experience a distinct glass ceiling. The adjusted gender wage gap is 9.5 percent, and this gap increases with education level, increasing to nearly 14 percent among college-educated workers. This paper contributes to the literature on workplace discrimination and gender wage inequality for younger workers, and it is original in reviewing the gender pay gap in Colombia using a primary dataset. Most of the work in this area has been done mainly in the developed countries and this research add to the findings which had focused on those nations

Sistema experto para motores asistido por temperatura (SEMAT)

Proyecto de investigación (Código: VIE 5402-1341-1301) Instituto Tecnológico de Costa Rica. Vicerrectoría de Investigación y Extensión (VIE), 2017El desarrollo de sistemas informáticos que tomen decisiones como expertos humanos en un ámbito particular con base en información, es un reto científi co/ tecnológico según el contexto y en motores eléctricos estos sistemas son prácticamente inexistentes. El proyecto SEMAT busca el desarrollo de un sistema experto que pueda diagnosticar motores el ectricos con la nalidad de mejorar la competitividad de la industria nacional. Para el desarrollo del sistema experto, este proyecto ha desarrollado una bancada de pruebas automatizada para someter los motores en estudio a distintas pruebas (casos). Adem as se ha desarrollado y programado el software de captura y análisis de datos, también se realizaron más de 60 pruebas a motores con base a un dise~no de experimentos factorial con la idea de estudiar sus distintos comportamientos. Adicionalmente, se aporta un modelo térmico y se trabajo con distintos tipos de algoritmos basados en metaheurísticas con la nalidad de encontrar soluciones al modelo. Sin embargo, los resueltos encontrados no permitieron ser implementados para el desarrollo del motor de inferencia del sistema experto basado en los parámetros de los modelos térmicos. Ante dicha problemática se aporta la de fición de nuevos indicadores que son calculados a partir de la potencias desperdiciadas en los motores. Dichos índices son calculados en tiempo real y almacenados por la aplicación informática. El prototipo de sistema experto utiliza como motor de inferencia una red neuronal tipo feed-forward. Dicha red fue entrenada con distintos casos (experimentos) y los resultados indican que a partir del monitoreo de los índices es posible realizar el diagnóstico del motor tanto en su transitorio térmico como en su estado estable. Esto es sumamente robusto en el sentido que el motor puede ser diagnosticado en sus primeros minutos de operación y no requiere que alcance su estabilidad térmica. Finalmente el prototipo fue comparado con el equipo comercial, encontrando que el sistema detecta un fallo más que los detectados por el sistema comercial, es decir el sistema comercial no es capas de detectar sobrecargas térmicas, lo que si realiza el sistema basado en redes neuronales

Multi-organ point-of-care ultrasound for COVID-19 (PoCUS4COVID): international expert consensus

COVID-19 has caused great devastation in the past year. Multi-organ point-of-care ultrasound (PoCUS) including lung ultrasound (LUS) and focused cardiac ultrasound (FoCUS) as a clinical adjunct has played a significant role in triaging, diagnosis and medical management of COVID-19 patients. The expert panel from 27 countries and 6 continents with considerable experience of direct application of PoCUS on COVID-19 patients presents evidence-based consensus using GRADE methodology for the quality of evidence and an expedited, modified-Delphi process for the strength of expert consensus. The use of ultrasound is suggested in many clinical situations related to respiratory, cardiovascular and thromboembolic aspects of COVID-19, comparing well with other imaging modalities. The limitations due to insufficient data are highlighted as opportunities for future research